The present invention relates to a two piece construction wheel for an automobile having a rim and a center disk separately formed.
Hitherto, a two piece wheel for an automobile has adopted a method in which flanges for welding are installed at a center disk and integrally connected to a rim by welding after the center disk is engaged with the internal circumference of the rim. And there has been antother method in which flanges for fixation with piercing holes for the insertion of bolts are fixed to the rim by welding and piercing holes are also drilled at the center disk so that the rim and the center disk are connected together by bolts and nuts.
However, fixation of a rim and a center disk by welding directly or indirectly has following problems in the structure of a two piece wheel for an automobile.
Welding is the most popularly utilized technique for the connection of similar metals as it is possible to reduce costs. It is, however, rather difficult to maintain certain level of quality such as strength of welding and accuracy in dimension, and in case of mass production of the same kind, it is possible to control diversity of the quality to some extent by the use of a special welding machine after finding out the optimum conditions in experiment. However, it is the general tendency to manufacture a small number and various kinds of products since the design (ordinally, the center disk) is the sales point of the two piece wheel for an automobile. The special welding machine for which time for preparation is necessary for each kind of product must be used, which results in the cost up factor adversely from the cost down factor through the cut off of the working hours which is one of its proper purposes. While the special welding machine is, unfortunately, inadequate an machine for the assembly of the two piece wheel for automobile in manufacturing a small number and various kinds of products, it is actually very difficult to assemble without such special machine.
Further, when either of a rim or a center disk of the two piece wheel for an autombile is damaged, the whole must be replaced, and such replacement was non-economical in the meaning of saving resources. And further, in an automobile equipped with a brake caliper of larger scale having much braking power, which is adopted specially in a front engine and front drive automobile, since the welding section and flange section for welding of the center disk or a prominence of other material for fixation are formed in the two piece wheel for an autombile, it can not be used for these automobiles.
As mentioned above, the present invention is to solve such problems as unevenness of quality in welding, low productivity of assembly in the manufacture of a small number and various kinds of products and difficulty of use to an automobile equipped with a brake caliper of larager scale due to mechanical structure of the connected section, which were shown in the two piece wheel asembled by the hitherto welding technique. The object of the present invention is to provide a two piece construction wheel for automobile which has merit in assembly and can be used to an autombile equipped with a brake caliper of larger scale with much braking power adopted recently to a front drive and front engine automobile.